Genetic and Phenotypic Correlations Between Linear Type Traits and Milk Yield in Sahiwal Cows

Abstract

The traits of economic importance in farm animals are mostly controlled by many gene pairs and hence show correlations. The knowledge of such correlations is very much needed while making multiple traits selection in farm animals. The present study was planned with the objectives to find out genetic and phenotypic correlations between linear type traits and milk yield in Sahiwal cows. Freshly calved 310 cows were scaled and scored for traits on a linear scale of 1-9 following the guide lines of International Committee on Animal Recording. The variance and covariance components were estimated using residuals or restricted maximum likelihood (REML) procedures. The linear mixed model was fitted for estimation of variance. Bivariate animal model analysis was performed for estimation of genetic and phenotypic correlations. Stature, angularity, rear udder height, fore teat length, dewlap width, foot angle, udder depth and rear udder width were significant sources of variation for score-day milk yield (P<0.05-P<0.001). The 305-day milk yield was influenced by linear type traits of rump angle, rump width, central ligament and rear udder width (P<.05-P<.001). Highest positive genetic correlations were for rear udder width with score-day milk yield (0.43±0.00) and 305 days milk yield (0.40±0.00). The highest negative genetic correlation (-0.27±0.00 and-0.23±0.00) was found of udder depth with score-day milk yield and 305-day milk yield. The phenotypic correlations ranged from-0.23±0.06 between udder depth and score-day milk yield to 0.54±0.04 between rear udder width and score-day milk yield. The genetic and phenotypic correlations will help to short list the type traits and put focus on those that are more important. The linear scoring in Sahiwal cattle should be initiated at public and private farms.

Appraisal of Linear Type Traits in Simmental Cows Reared on High Altitude of Eastern Turkey

“…In general, the correlation values were in between lower and medium range, and most of the correlations were less than 0.20. Similar results were already reported by Duru et al (2012) and Khan & Khan (2016). The strongest positive phenotypic correlations (r= 0.43) were estimated between fore udder attachment and udder depth.…”

The Effect of Non-Genetic Factors on the Linear Type Traits in Brown Swiss Cows Reared in Eastern Region of Turkey

“…Rear udder attachment width was negatively correlated with angularity (-0.18), rear leg (side view) (-0.15), rump angle (-0.18), fore udder attachment (-0.13) ( Table 4). As for this study, negative and low correlation values among rear udder attachment width with angularity, rear leg (side view), rump angle, and fore udder attachment was also indicated by Khan et al, (2008) in Sahiwal cows.…”

“…Phenotypic correlations among body and feet and leg traits were in low to medium range as reported by (Khan et al, 2008). Correlations ranged from 0.37 between body depth and chest width to -0.46 between udder depth and teat length (Table 4).…”

“…The type traits are body components of a cow which is related with milk production. The linear type traits have an influence on milk yield (Khan and Khan, 2016). They are utilized to define the dairyness of a cow and they are the basis of modernday classification system (Dubey et al, 2014).…”

Estimation of heritability and genetic correlations between milk yield and linear type traits in primiparous Holstein-Friesian cows

“…In their research of correlations between type traits and milk yield, Bohlouli et al (2015) established positive correlations for all type traits that varied from 0.02 for FTP to 0.26 for ANG. In addition, Khan and Khan (2016) obtained genetic correlation values ranging from −0.23 for UD to 0.40 for RUH.…”